Intrinsic labelling of different foods with stable isotope of zinc ( 67 Zn) for use in bioavailability studies

Abstract

Intrinsically-labelled foods are required to validate extrinsic-labelling techniques used to study the bioavailability of trace elements. Wheat ( Triticum aestivum ), peas ( Pisum sativum ), goat's milk, human milk, eggs and chicken meat were selected for intrinsic-labelling studies with 67 Zn. Peas were grown hydroponically in enriched nutrient solution and wheat was grown in sand and watered with enriched nutrient solution. Some of the wheat plants were also given stem injections of 67 Zn solution. Eggs and chicken meat were prepared by administering 67 Zn intravenously to chickens, and human milk was collected after an oral dose of 67 Zn in a cola drink. All the foods investigated were sufficiently enriched with 67 Zn for Zn absorption studies except wheat prepared by the sand and water-culture method.